Going to try sell you the party by sharing our favorite things about the party nights:
You get to wear stuff you would never get away with wearing to work
<a href="https://www.flickr.com/photos/2tiggies/8090781080" title="Good to go? by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8327/8090781080_35d3158ece.jpg" width="500" height="408" alt="Good to go?"></a>
Specially themed decorations and merchandise are put out once the party starts. Of course the usual decorations are still up too but it really tops it off.
<a href="https://www.flickr.com/photos/2tiggies/8090774665" title="DSC_0159 by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8335/8090774665_f250a62737.jpg" width="500" height="395" alt="DSC_0159"></a>
<a href="https://www.flickr.com/photos/2tiggies/8517043156" title="Decked for the party (Main Street Confectionery) by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8241/8517043156_878f46539b.jpg" width="332" height="500" alt="Decked for the party (Main Street Confectionery)"></a>
(Next one was supposed to be a test for exposure settings on the camera but decided to keep it - liked the spooky look). Cast members all dressed up for the party. There is a very different atmosphere during the party compared to a 'normal' day or night at the park. The MK takes on a completely unique ambiance which is difficult to describe.
<a href="https://www.flickr.com/photos/2tiggies/8090756535" title="Ghost hosts by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8053/8090756535_b177ffe203.jpg" width="500" height="332" alt="Ghost hosts"></a>
I think part of it is down to the party lighting
<a href="https://www.flickr.com/photos/2tiggies/8236642278" title="Trick or Treat @ Jungle Cruise by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8485/8236642278_88a8eb0e21.jpg" width="500" height="332" alt="Trick or Treat @ Jungle Cruise"></a>
Frontierland looks a little different
<a href="https://www.flickr.com/photos/2tiggies/8090753491" title="DSC_0213 by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8332/8090753491_272b84815f.jpg" width="500" height="302" alt="DSC_0213"></a>
<a href="https://www.flickr.com/photos/2tiggies/8127608853" title="After the party by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8471/8127608853_e8466c2c2f_c.jpg" width="800" height="494" alt="After the party"></a>
<a href="https://www.flickr.com/photos/2tiggies/8597998257" title="MK12-0950 by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8506/8597998257_785f35b8cd_c.jpg" width="800" height="531" alt="MK12-0950"></a>
Light projections all over the surfaces at random
<a href="https://www.flickr.com/photos/2tiggies/8127647874" title="DSC_0361 by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8329/8127647874_e3f2dc137a.jpg" width="500" height="479" alt="DSC_0361"></a>
<a href="https://www.flickr.com/photos/2tiggies/8162642267" title="Party lighting by Lee, on Flickr"><img src="https://farm8.staticflickr.com/7248/8162642267_e1ee3b5ffc.jpg" width="500" height="332" alt="Party lighting"></a>
<a href="https://www.flickr.com/photos/2tiggies/8127522671" title="MNSSHP Lighting in Tomorrowland by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8331/8127522671_a42101f7b0_c.jpg" width="800" height="531" alt="MNSSHP Lighting in Tomorrowland"></a>
<a href="https://www.flickr.com/photos/2tiggies/8237043059" title="DSC_0357 by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8062/8237043059_99371e11d0_c.jpg" width="800" height="531" alt="DSC_0357"></a>
Strange encounters
<a href="https://www.flickr.com/photos/2tiggies/8127606206" title="Grim Grinning Ghosts come out to socialize by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8473/8127606206_3f6b8f6523.jpg" width="332" height="500" alt="Grim Grinning Ghosts come out to socialize"></a>
Themed snacks (not sure where they do these now that Main Street Bakery is a Starbucks)
<a href="https://www.flickr.com/photos/2tiggies/8127564482" title="Main Street Bakery party offerings by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8329/8127564482_1ac2ac25e3.jpg" width="500" height="332" alt="Main Street Bakery party offerings"></a> <a href="https://www.flickr.com/photos/2tiggies/8127563806" title="Main Street Bakery party offerings by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8326/8127563806_5f26b4c555.jpg" width="500" height="332" alt="Main Street Bakery party offerings"></a>
The Villains Mix n Mingle Show takes place several times on a schedule in front of the castle. It's short enough not to take much time out of your party but really worth stopping for if you can do it.
<a href="https://www.flickr.com/photos/2tiggies/8090734055" title="Villains Mix n Mingle by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8475/8090734055_1a9a677757_z.jpg" width="640" height="420" alt="Villains Mix n Mingle"></a>
<a href="https://www.flickr.com/photos/2tiggies/8090738642" title="Villains Mix n Mingle by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8473/8090738642_26cd9a2257.jpg" width="500" height="332" alt="Villains Mix n Mingle"></a>
<a href="https://www.flickr.com/photos/2tiggies/8090733605" title="Villains Mix n Mingle by Lee, on Flickr"><img src="https://farm9.staticflickr.com/8325/8090733605_db0ee21902.jpg" width="500" height="332" alt="Villains Mix n Mingle"></a>